High-nickel Materials Research Articles

Insights into the Performance Enhancement of Co and Mn Doped LiNiO2 Cathodes Using Synchrotron Techniques

High nickel materials, particularly LiNiO2 (LNO) with energy densities >200 mAh/g, are promising candidates and have attracted considerable interest as cathode materials for a new generation of energy storage devices [1]. However, LNO faces challenges related to low thermal stability and capacity degradation during cycling. To address these issues, several strategies have been employed, including bulk morphology modifications, electrolyte engineering, and the incorporation of metals such as Mn, Co, and Mg [2]. Doping has been identified as an effective approach to mitigate anisotropic variations in lattice parameters during cycling, thereby reducing capacity fading, improving electrochemical performance, structural and thermal stability [3]. Previous research has concluded that certain dopants are necessary to stabilize LNO cathodes over long-term cycling. Cobalt, manganese and aluminum can improve surface stability and reduce oxidative decomposition of the electrolyte. Furthermore, manganese can suppress phase transitions and contribute to higher structural stability [4]. Nonetheless, there is a significant gap in our understanding of many factors that affect the electrochemical performance of LNO cathodes.We are exploring Co and Mn doped LNO cathodes using advanced synchrotron radiation-based techniques. Using X-ray absorption spectroscopy, the X-ray absorption near edge structure (XANES) reveals the change of oxidation states as a function of the state of charge (SoC) and demonstrates stable electrochemical reversibility for LiNi0.95Co0.05O2 (NC). Notably, the edge energy positions remain stable in discharged states for NC and LiNi0.95Mn0.05O2 (NM). The extended X-ray absorption fine structure (EXAFS) provides insights into the local atomic bonding and coordination of the transition metal of interest. EXAFS reveals that Co stabilizes the local structure even with long-term cycling. Furthermore, combining X-ray transmission with spectroscopy (TXM-XANES) enables detailed chemical and morphological studies of LNO across several SoCs through both operando and post-mortem characterization. LNO, NC and NM cathodes show spherical-shape morphology, and LNO and NC cathodes show crack formation after the first charge. The edge energy positions remain consistent within the electrode with no local (interparticle) heterogeneity, but there is noticeable variation between pristine and charged cathodes. Complementary to this, we are studying the cathode-electrolyte interface (CEI) using laser ablation mass spectroscopy. By analyzing the Li content and other CEI species during charging, we observe significant electrolyte decomposition resulting in the formation of a dense CEI layer [5,6]. Although this layer is initially unstable, it stabilizes after several charge/discharge cycles. Our work provides insight into the challenges of high-energy density, high-nickel cathode design and enhanced cathode performance attributed to the dopants influence.

Water-Based Pickering Emulsion Scheme for One-Step Washing and Coating High-Ni Layered Cathode for Lithium-Ion Batteries

High-nickel layered oxides have gained significant attention in a lithium-ion rechargeable battery (LIB) system due to their high energy density[1]. However, their severe anisotropic volume changes upon de/lithiation result in mechanical degradation issues, ultimately deteriorating cycle life[2]. Moreover, the unstable surface of the nickel element and the high-temperature synthesis conditions contribute to the residual lithium on the surface, giving rise to electrode engineering hurdles such as slurry gelation and gas evolution[3]. To prevent these major problems, In this research, we propose an innovative water-based Pickering emulsion CNT coating scheme to increase the mechanical strength and residual lithium issues, simultaneously[4]. This approach offers a straightforward physical coating process, facilitating rapid water-washing during CNT coating and minimizing surface damage caused by water in vulnerable high-nickel materials. Using ethyl cellulose in the CNT coating process facilitates stable CNT dispersion and emulsion formation. Additionally, ethyl cellulose forms a hydrophobic layer on the active material surface, addressing moisture sensitivity issues post-water-washing[5]. The synergistic effects of CNT coating and efficient removal of residual lithium enhance the electrochemical cycle life, achieving over a 20% increase in capacity retention compared bare washing after 200 cycle at 1C. This economically and environmentally advantageous water-based coating method is applicable not only to high-nickel cathodes but also to other battery materials requiring CNT coating for enhancing electronic conductivity and suppressing volume change.Reference[1] Nature Energy. 2020, 5, 26–34[2] Chem. Mater . 2018 , 30, 3, 1155–1163[3] ACS Energy Lett. 2021 , 6, 3, 941–948[4] Adv. Energy Mater.2020, 10, 2001216 [5] Chem. Mater. 2023, 35, 5150 −5159

Stable and Fast Ion Transport Electrolyte Interfaces Modified with Novel Fluorine- and Nitrogen-Containing Solvents for Ni-Rich Cathode Materials.

Ternary nickel-rich layered oxide LiNi0.8Co0.1Mn0.1O2 (NCM811) is recognized as a cathode material with a promising future, attributed to its high energy density. However, the pulverization of cathode particles, structural collapse, and electrolyte decomposition are closely associated with the fragile cathode-electrolyte interphases (CEI), which seriously affect the electrochemical performances of ternary high-nickel materials. In this paper, fluorine- and nitrogen-containing methyl-2-nitro-4-(trifluoromethyl)benzoate (MNTB) was selected, which was synergistically regulated with fluoroethylene carbonate (FEC) to generate a robust CEI film. The preferential decomposition of MNTB/FEC results in the formation of an inorganic-rich (Li3N, LiF, and Li2O) CEI film with uniformly dense and stable characteristics, which is conducive to the migration of Li+ and the stability of the NCM811 structure and enhances the cycling stability of the battery system. Simultaneously, MNTB effectively suppresses the adverse reaction associated with increased polarization caused by higher interface impedance due to conventional single FEC additives, further improving the rate capability of the battery. Moreover, MNTB/FEC can effectively eliminate HF, preventing its corrosion on the NCM811 cathode. Under the synergistic effect of MNTB/FEC, after 300 discharge cycles at a high cutoff voltage of 4.3 V and a current density of 1 C (2 mA cm-2), the discharge capacity of the NCM811||Li battery was 150.12 mA h g-1 with a capacity retention of 81.10%, while it was only 32.8% for the standard electrolyte (STD). The discharged capacity of the MNTB/FEC-containing battery was about 115.43 mA h g-1 at the high rate of 7 C, which was considerably higher than that of the STD (93.34 mA h g-1). In this study, the designed MNTB as a novel solvent synergistically regulated with FEC will contribute to the enhanced stability of NCM811 materials at high cutoff voltages and at the same time provide an effective modified strategy to enhance the stability of commercial electrodes.

Improving storage performance and lattice oxygen stability of single crystal LiNi0.925Co0.03Mn0.045O2 by integrating utilization of surface residual lithium and lattice modulation

In lithium-ion batteries, Ni-rich single crystal cathode material (Ni > 90 %) is a promising cathode material, but it has not yet been put into commercial application due to defects such as structural degradation, air sensitivity and thermal instability. In this paper, the residual lithium compounds on the surface of high-nickel materials are not useless. Li3PO4 coated and Mg2+ doped single crystal cathode materials (SC-NCM-MP) were successfully prepared by precisely controlling the amount of MgHPO4 by titration and reacting with lithium compounds left on the surface of LiNi0.925Co0.03Mn0.045O2 (SC-NCM) cathode materials. The SC-NCM-MP samples exhibit better lattice oxygen stability, Li-ion mobility, storage performance and electrochemical performance, with a retention of 89.36 % after 100 cycles, which is much higher than 79.78 % of SC-NCM.

Performance Enhancement of Nickel Manganese Cobalt Oxide Cathodic Material for Solid-State Battery Technology by Surface Engineering

Batteries as any other electronic devices are affected by parasitic phenomena including physical processes and chemical reactions occurring within the battery materials as well as their interfaces. The phenomena lead to degradation in performance, impose operation restrictions and potentially make devices unsafe.Solid-state, lithium-metal-based, batteries show promise to meet electric vehicle market requirements, but technical challenges to overcome rapid degradation and cost-effective processing remains. Cathode/electrolyte interfacial side reactions can lead to passivating layer formation, thus increasing cell resistance, unwanted additional overvoltage, and ultimately capacity loss. These phenomena are exacerbated in solid-to-solid contact between solid state electrolytes, active materials, and electronic conductive agents. Therefore, electrode manufacturing design is required to mitigate these issues.Within this work we have evaluated Spray Drying (SD) and Atomic Layer Deposition (ALD) coating processes to engineer the cathode/ electrolyte interface of SSBs, thus improving performance and overall cell cycle life. Cathode materials coating is utilised as an effective strategy to mitigate the degradation of the interface. SD is classically utilised in the food and pharma industries, and it has recently been expanded to include the synthesis/shaping of battery electrode materials as a versatile and robust methodology that can be easily scaled up. ALD is a widely exploited technique in the semiconductor (SC) industry based on self-limiting chemical reactions to deposit stoichiometrically-fixed, defect-free and nanometric-thick materials on surfaces. As such, the application of ALD to coat powders in the battery community is innovative and currently under development.Cathodic materials such as NMC (Nickel Manganese Cobalt Oxides) have been investigated, as the need for improving the capacity retention is strong for high-content (>80%) nickel cathodes. Indeed, ALD utilised to coat NMC powder provides a nanometric thick layer of a dielectric but ionic conductive metal oxide. Optimisation of aluminium oxide shell on a core of polycrystalline high nickel material has been investigated with surface engineering. In parallel, we have been exploring the benefit of SD to create an NMC811 powder showing a decorated structure using two different approaches. Indeed, we have either used preformed metal oxide nanoparticles dispersed in an NMC suspension or synthesised a metal oxide layer on top of the NMC in-situ by a chemical reaction during the spray process.Morphological and chemical characterisation of the products have been crucial to develop the coating processes. Electrochemical Impedance Spectroscopy (EIS) probed the engineered cathode/ electrolyte interface within half- and full-coin cell configuration. Rate performance and long-term cycling evaluation has driven the design of an oxide-based lithium metal solid state battery.Alumina coated powder NMC showed longer capacity retention than raw materials when tested in coin cell batteries. The cells were assembled using thin lithium metal anode, Lithium-Lanthanum Zirconium Oxide (LLZO) electrolyte, and surface-engineered NMC811 supported by aluminium current collector. Key words:Surface Engineering, Coatings, Solid-State Batteries (SSB), Spray Dry, Atomic Layer Deposition (ALD), Preformed Nanoparticles, Nickel Manganese Cobalt Oxide (NMC), NMC811, Lithium Lanthanum Zirconium Oxide (LLZO), Interfaces.

Tailoring electrolyte distributions to enable high-performance Li3PS4-based all-solid-state batteries under different operating temperatures.

Li3PS4 shows great potential as solid electrolyte for all-solid-state lithium batteries (ASSLBs) due to its high conductivity and excellent mechanical properties. However, its poor interfacial stability with bare high-nickel materials in the cathode mixture inhibits the energy density and electrochemical performances of the correspondingLiNi0.6Mn0.2Co0.2O2/Li3PS4/Li-In battery. The Li3InCl6 electrolyte with good electrochemical/chemical stability with bare NCM622, which acts both as a Li-ion additive in the cathode and as an isolation layer to isolate the direct contact between the sulfide electrolytes and active materials, providing superior solid/solid interface stabilities in the assembled battery. XPS and TEM results confirm that this strategy can mitigate the side reactions.This grading utilization of different solid electrolytes can greatly alleviate the poor electrochemical stability, yielding smaller interfacial resistances. The corresponding battery delivers high discharge capacities at various C-rates under different operating temperatures. It delivers a much higher initial discharge capacity of 187.7 mAh g-1at 0.1C with a coulombic efficiency of 87.6% at RT. Moreover, it can show highly reversible capacity with excellent cyclability when operated at 0 and -20 oC. This work provides a hierarchical utilization strategy to fabricate sulfide electrolytes-based ASSLBs with high energy density and superior cycling performance combined with highly-oxidation cathode materials.

In Situ Inducing Spinel/Rock Salt Phases to Stabilize Ni-Rich Cathode via Sucrose Heat Treatment

Nickel-rich cathode materials have attracted widespread interest due to their high capacity; however, the structure is prone to degradation and collapse during cycling, resulting in poor stability performance and safety, hindering the development of high-nickel cathode materials. Here, we propose a straightforward method to consume oxygen on the surface of primary particles during the high-temperature calcination process of precursors, inducing the coupled rearrangement of surface cations, resulting in the in situ generation of a nano-sized mixed spinel/rock salt defect phase, which is confirmed by high-angle annular dark-field scanning transmission electron microscopy. LiNi 0.8 Co 0.1 Mn 0.1 O 2 modified with mixed phase not only can reduce side reactions with the electrolyte, resulting in fewer by-products such as LiF and Li 2 CO 3 , preventing the formation of excessively thick cathode–electrolyte interface layers, but also can avoid irreversible phase transitions and prevents lattice mismatches. As a result, the cycling performance has been improved to some extent, benefiting from structural stability. In addition, the special 3-dimensional structure of the spinel phase allows the material surface to expand ion transport channels and enhance multiplicative performance. Therefore, this study provides a new perspective on the modification of high-nickel materials and extends the application of nickel-rich materials.

Face-lifting the surface of LiNi0.8Co0.15Al0.05O2 cathode via Y(PO3)3 to form an in situ triple composite Li-ion conductor coating layer with the enhanced electrochemical performance

Due to the assets such as adequate discharge capacity and rational cost, LiNi0.8Co0.15Al0.05O2 (NCA), a high-nickel ternary layered oxide, is regarded to be a favorable cathode contender for lithium-ion batteries. However, the superior commercial application is restricted by the surface residual alkaline lithium salt (LiOH or/and Li2CO3) of nickel-rich cathode materials, which will expedite the disintegration of the structure and the engendering of gas (CO2). Therefore, in this paper, we devise and fabricate a Y(PO3)3 modified LiNi0.8Co0.15Al0.05O2 (NCA), intending to optimize the surface residual alkaline lithium salt (antecedent deportation of H2O and CO2) while forming an in situ triple composite Li-ion conductor coating (Y(PO3)3-Li3PO4-YPO4) to enhance the electrochemical behavior. Under this method, the 2 mol% Y(PO3)3 modified NCA electrode reveals exceptional rate capability (5 C/156.3 mAh g−1) and extraordinary cycle stability after 200 cycles (2 C/88.3%), whereas the original sample is only 5 C/123.1 mAh g−1 and 2 C/71.2% after 200 cycles. Conspicuously, even under the draconian circumstances of the high temperature and the high rate at 55 °C/1 C, the 2 mol% Y(PO3)3 modified NCA electrode sustains a high reversible capacity, with an admirable capacity retention rate of 89.4% after 100 cycles. These contented results signify that the surface remodeling tactic presents a viable scheme for ameliorating high-nickel materials’ performance and appropriateness.

Controlled Dy-doping to nickel-rich cathode materials in high temperature aerosol synthesis

Layered nickel-rich materials are promising next-generation cathode materials for lithium ion batteries due to their high capacity and low cost. However, the poor thermal stability and longtime cycling performance hinders the commercial applications of high nickel materials. Doping with heteroatoms has been an effective approach for improving electrochemical performance of cathode materials. Controlling doping concentration and geometrical distribution is desired for optimal electrochemical performance, but it is challenging in traditional co-precipitation methods. In this work, controlled dysprosium (Dy) doping to NCM811 was studied in an aerosol synthesis method by controlling the precursor concentrations and heating parameters. The obtained materials were characterized by SEM, XRD, and XPS, and their electrochemical properties and thermal stability were evaluated. By controlling the doping concentration (1.5%), Dy-doped NCM811 was improved simultaneously in long-term cycling and high-rate performance. The thermal-chemical stability of the Dy-doped cathode materials was examined in a microflow reactor with a mass spectrometer. The results showed that Dy-doping shifted the O2 onset temperature to a higher temperature and reduced O2 release by 80%, thus dramatically increasing the thermal-chemical stability and improving the fire safety of cathode materials. Since high temperature aerosol synthesis is a low-cost and scalable method, the findings in this work have broad implications for commercial synthesis of novel materials with controlled doping modification to achieve high electrochemical performance and safety in lithium ion batteries.

The effects of multiple metals (K, Cu, Al) substitution on LiNi0.66Co0.20Mn0.14O2 for lithium-ion batteries

The high-nickel ternary cathode material LiNixCoyMn1-x-yO2 has high theoretical capacity and can be filled the power density requirement of a foot-powered car. It is placed on high expectations. However, Li/Ni mixing occurred during charging and discharging, resulting in poor cycle performance of the material. The related literatures have found that the K, Cu, and Al doping can improve the cycle performance of high-nickel materials. In this paper, we designed the orthogonal experiment and synthesized [Li(1-y)Ky](Ni0.66Co0.20Mn0.14)(1-x-z)[CuxAlz]O2 (x,y,z) = 0.00, 0.01, 0.02, 0.03, 0.04) cathode materials by the co-precipitation method. The initial charge–discharge specific capacity of [Li0.99K0.01](Ni0.66Co0.20Mn0.14)0.94[Cu0.03Al0.03]O2 can reach 214.7 mAh/g and 210.8 mAh/g, coulomb efficiency is 98.18%. After 30 cycles at 1C, capacity retention is 87%. According to the orthogonal test, results are as follows: about initial discharge specific capacity of the material, K presents the greatest effect, followed by Al, with minimal effect on Cu. However, Al has the greatest influence on the capacity retention rate of the material at high rate, followed by K element and Cu element. This will provide guidance for the future study of the modification of doping metal elements in high-nickel ternary lithium ion cathode materials.

Impact of Dopants (Al, Mg, Mn, Co) on the Reactivity of LixNiO2 with the Electrolyte of Li-Ion Batteries

First-principles computation of bulk O binding energies and Bader charges revealed the importance of Li content on thermal decomposition of charged high-nickel positive electrode materials for Li-ion batteries (LixNi1-yMyO2, 0 < x < 1, y = 0, 0.05, M = Al, Mg, Mn, Co). The impact of individual dopants on the safety of these materials was studied using thermogravimetric analysis (TGA) and accelerating rate calorimetry (ARC) at two different states of charge corresponding to materials with two different Li contents. It was found that thermal stability strongly depends on the Li content of the material and that dopants serve to increase thermal stability by reducing the amount of Li removed from the material at a given voltage. This work sheds light on an unavoidable trade-off between high capacity and thermal stability for high-nickel materials.

Synthesis Method for Long Cycle Life Lithium-Ion Cathode Material: Nickel-Rich Core-Shell LiNi0.8Co0.1Mn0.1O2.

High-nickel materials with core-shell structures, whose bulk is rich in nickel content and the outer shell is rich in manganese content, have been demonstrated to improve cycle stability. The high-nickel cathode material LiNi0.8Co0.1Mn0.1O2 is a very promising material for lithium-ion batteries; however, its low rate performance and especially cycle performance currently hamper further commercialization. This study presents a new synthesis method to prepare this core-shell material (LiNi0.8Co0.1Mn0.1O2@ x[Li-Mn-O], x = 0.01, 0.03, 0.06). Electrochemical data show that LiNi0.8Co0.1Mn0.1O2@ x[Li-Mn-O] ( x = 0.03, CS-0.03) exhibits the best high-rate performance, cycle stability, and thermal stability. The initial discharge capacity of the core-shell sample CS-0.03 is 118 mAh g-1, which is almost the same as the discharge capacity of pristine LiNi0.8Mn0.1Co0.1O2 (117 mAh g-1) at the rate of 10 C in the voltage range of 3.0-4.3 V. Notably the capacity decay of CS-0.03 is 18.4% after 200 cycles compared to 27% decay in capacity of the pristine sample. Furthermore, CS-0.03 exhibits better thermal cycling stability. The capacity retention of the CS-0.03 sample reached 65.1% which is over 1.3 times than that of the pristine one, whose capacity retention is 49.2% after 105 cycles (55 °C). Evidently, the core-shell structured CS-0.03 sample has excellent cycle stability and this synthesis method can be applied to other cathode materials.

The effect of Co3O4 & LiCoO2 cladding layer on the high rate and storage property of high nickel material LiNi0.8Co0.15Al0.05O2 by simple one-step wet coating method

Co3O4 & LiCoO2 complex cladding layer with nutty-cake structure effectively improves high rate and storage properties of high nickel material LiNi0.8Co0.15Al0.05O2 (NCA), using a simple one-step wet-coating process, and the degradation of NCA is successfully restrained. The structure and morphology of samples are demonstrated by X-ray diffraction (XRD), scanning electron microscope (SEM), and field-emission high resolution transmission electron microscope (FEHRTEM). The elemental composition and distribution are determinate by energy dispersive spectrometer (EDS). In comparison with pristine NCA, 0.25wt.% Co3O4-modified NCA has a better electrochemical performance with more capacity of approximate 30mAhg−1 at 1C after 150 cycles. At 5C and 10C, it also exhibits better capacity retentions and higher capacities. After exposed to the air for 100 days, 0.25wt. % Co3O4-modified NCA still shows better electrochemical performance than pristine NCA stored at the same condition. The improved comprehensive performance of Co3O4 & LiCoO2 coated NCA is related with the facile coating method in which Co3O4 is formed and the lithium impurity on NCA surface is consumed to produce LiCoO2 concurrently during calcining process. The reaction mechanism of Co3O4 & LiCoO2 composite layer is analyzed using the cyclic voltammetry (CV) and the electrochemical impedance spectroscopy (EIS).

Analysis of the Ductile-to-Brittle Transition Temperature Shift in a Commercial Power Plant With High Nickel Containing Weld Material

Abstract Plant specific surveillance programs that ideally include all relevant materials and materials combinations that are subjected to neutron irradiation during operation address the degradation due to irradiation of the reactor pressure vessel material for nuclear electric power plants. Plant specific surveillance programs are not unique to the two power plants treated in this study. The current Swedish regulatory system does, however, call for a fairly rigid approach within the surveillance program. In the Swedish case, this means that there is a plant specific predetermined inspection∕test program that has to be followed in order to verify the operability of the power plant and also to verify the operational limits with respect to pressure∕temperature effects on a repetitive basis. The two pressurized water reactor plants Ringhals 3 and 4 have in common that the weld metal used for the butt welds of the reactor pressure vessel is a high nickel type material, above the current limits of the NUREG Reg. Guide 1.99, rev. 2. In the original state, the high nickel content provides excellent fracture toughness in the unirradiated material condition and a low ductile-to-brittle transformation temperature (DBTT). It has, however, been highlighted in several studies that high nickel materials exhibit a very large DBTT shift as a consequence of irradiation, and also that the precipitates that form during the irradiation are not as easily controlled during a heat treatment to remove the irradiation damage as are the copper rich clusters. This paper will present the current state of the art regarding these effects as observed in the weld metal specimens. The paper will present the results from the Charpy V notched and fracture mechanics specimen test encapsulated in the Ringhals Units 3 and 4 surveillance programs. The results from the Ringhals Units 3 and 4 surveillance programs show that there is a need for corrective action to be taken in order to ensure 60 y of operability for the two power plants.

Localized Corrosion and Stress Corrosion Cracking of Candidate Materials for High-Level Radioactive Waste Disposal Containers in U.S.: A Critical Literature Review

ABSTRACTThree iron-based to nickel-based austenitic alloys and three copper-based alloys are being considered in the United States of America as candidate materials for the fabrication of high-level radioactive waste containers. The austenitic alloys are Types 304L and 316L stainless steels as well as the high-nickel material Alloy 825. The copper-based alloys are CDA 102 (oxygen-free copper), CDA 613 (Cu-7A1), and CDA 715 (Cu-3ONi). Waste in the forms of spent fuel assemblies from reactors and borosilicate glass will be sent to a proposed repository at Yucca Mountain, Nevada. The decay of radionuclides will result in the generation of substantial heat and in gamma radiation.

The low temperature impact properties of the meteorite hoba

Charpy V‐notch impact specimens prepared from the high nickel ataxite Hoba have been tested at 77° and 195°K. The specimen tested at 77°K was fully brittle, and the one tested at 195°K was fully ductile. It is concluded that the transition to complete brittleness occurs below about 140°K or 150°K. Thus, high nickel material such as this is ductile at the ambient temperature of an asteroid, which is about 150°K, and does not fragment in a brittle manner when meteoritic material is formed by the collision of asteroids. This confirms a hypothesis put forward by Remo and Johnson [1974] according to which this failure of high nickel material to fragment explains the large average size of high nickel meteorites. The microstructure of Hoba was studied using optical microscopy, scanning electron microscopy, and electron beam microprobe analysis. It was found, in agreement with the results of earlier workers, that Hoba has a fine plessitic structure with prolific small mineral inclusions. Some troilite inclusions were shown to have transverse bands of daubreelite within them.

The Kapitza resistance for a helium film

Co3O4 & LiCoO2 complex cladding layer with nutty-cake structure effectively improves high rate and storage properties of high nickel material LiNi0.8Co0.15Al0.05O2 (NCA), using a simple one-step wet-coating process, and the degradation of NCA is successfully restrained. The structure and morphology of samples are demonstrated by X-ray diffraction (XRD), scanning electron microscope (SEM), and field-emission high resolution transmission electron microscope (FEHRTEM). The elemental composition and distribution are determinate by energy dispersive spectrometer (EDS). In comparison with pristine NCA, 0.25 wt.% Co3O4-modified NCA has a better electrochemical performance with more capacity of approximate 30 mAh g−1 at 1C after 150 cycles. At 5C and 10C, it also exhibits better capacity retentions and higher capacities. After exposed to the air for 100 days, 0.25 wt. % Co3O4-modified NCA still shows better electrochemical performance than pristine NCA stored at the same condition. The improved comprehensive performance of Co3O4 & LiCoO2 coated NCA is related with the facile coating method in which Co3O4 is formed and the lithium impurity on NCA surface is consumed to produce LiCoO2 concurrently during calcining process. The reaction mechanism of Co3O4 & LiCoO2 composite layer is analyzed using the cyclic voltammetry (CV) and the electrochemical impedance spectroscopy (EIS).